Many problems stem from the growth of roots in underground sanitary and storm sewers. For example, if plant roots are left untreated, they can cause line blockages, back-ups, and sewage system failure. Ultimately, such root growth typically causes shutdown of the sewer. It is therefore necessary to partially or totally remove roots from sewage lines.
The removal of plant roots from sewage lines poses several problems. In particular, when de-rooting a sewer, care must be taken to avoid damaging the above-ground foliage which is typically on private land and planted and cared for by a homeowner. Although the above-ground foliage may be delicate, it is important to eliminate as much of the root as possible to minimize its regrowth. If a root is not completely removed, as when one branch of a root is cut near its top, multiple roots may sprout from that branch which could aggravate the root problem.
Various methods that have been employed to remove such roots have hertofore proven unsatisfactory. The methods that have been used to combat the root blockage problem include the use of mechanical rodding machines, high pressure flushing machines, and various snaking and plumbing devices.
For example, to minimize or remove root blockage, high pressure flushing machines have been used. Such machines typically drive a hydraulic motor, residing at the end of a sewer flushing hose, and are used with various sized circular and rigid cutting devices such as saws. However, the use of such rigid saws poses several problems. In particular, due to the precision required and the risk of damage to the inside wall of a pipeline, operators of rigid saws are often unable or unwilling to use a large enough saw blade inside the sewage line which is necessary to fully cut the root. When that problem is coupled with the circumstances typically existing in sewage lines, such as the presence of offset joints or protruding tap-ins typically encountered in the field, often an undersized blade will be used. An undersized blade while minimizing these problems only partially removes root blockage. Such partial removal reduces the pipeline's effective inside diameter in comparison to its original, unobstructed diameter. Consequently, the hydraulic pump-motor system experiences reduced flow capacity and increased loading. Moreover, even an undersized rigid saw blade can get jammed in the sewer line which could damage the sewer cleaning equipment and require that the underground sewer line and the hydraulic motor be excavated and repaired or even replaced.
Another method for controlling root growth has employed the running of chains or snakes through a line. However, that method tends to have a hammering effect on the inside surface of a pipeline which could cause excessive wear or damage to the sewage line.
Another method for controlling roots employs spring-loaded, three-armed cutter blades. As is known in the art, sewage lines are typically substantially horizontal and slightly pitched to allow for sewage to flow through the line under gravity from one end of the line, typically where a manhole is located, to another end, typically where sewer cleaning equipment is based. Spring-loaded blades are disadvantageous since they cannot effectively operate in the upstream direction of the pipeline. In particular, due to the conical orientation of the rotating blades, if the cutter were operated in an upstream, concave direction, it would likely become stuck in the line once it encounters a root or other obstruction. Therefore, an operator of a sewer cleaning device must remember to start the cleaning device at the upstream end of the sewer line and allow it to sweep the line in a downstream direction away from the manhole and toward the sewer cleaning equipment. In addition, if the hydraulic motor and associated cleaning equipment is initially on the downstream end of the pipeline, the operator of the cleaning equipment is inconvenienced because the cleaning equipment must be moved upward to the upstream side of the pipeline before cleaning the line.
One purpose of the present invention, therefore, is to remove objects from the inside of pipelines, such as plant roots, without causing the root-removing equipment to get jammed in the line.
Another object of the present invention is to reduce the likelihood of damaging the line while providing for the maximum removal of objects throughout the full pipe diameter of the line.
Another object of the present invention is to allow a pipeline obstruction removal device to operate in either longitudinal direction toward either end of a pipeline.
Another object of the present invention is to provide a device that can easily operate in and be adaptable to pipelines having several different inside diameters.
Another object of the present invention is to provide a device for removing severely-impacted objects from pipelines. Still another object of the present invention is to provide an effective obstruction or plant root removing device adaptable to various hydraulic motors.